Microelectronic contact structures, and methods of making same

• US 6,520,778 B1
• Filed: 02/13/1998
• Issued: 02/18/2003
• Est. Priority Date: 02/18/1997
• Status: Expired due to Fees

• Current Assignee: FormFactor Incorporated
• Original Assignee: FormFactor Incorporated
• Inventors: Mathieu, Gaetan L., Eldridge, Benjamin N., Grube, Gary W., Khandros, Igor Y.
• Primary Examiner(s): Abrams, Neil
• Application Number:
  US09/023,859
• Time in Patent Office: 1,831 Days
• Field of Search: 324/754, 324/761, 324/762, 439/66, 439/81, 205/78
• US Class Current: 439/66
• CPC Class Codes: G01R 31/2886 Features relating to contacting the IC under test, e.g. probe heads; chucks G01R31/2865 takes precedence, test connections, e.g. test sockets, or probes per se, G01R1/04 or G01R1/06
• CPC Class Codes: H01H 1/0036 Switches making use of microelectromechanical systems [MEMS] for electromagnetic relays H01H50/005; for electrostatic relays H01H59/0009
• CPC Class Codes: H01L 21/67288 Monitoring of warpage, curvature, damage, defects or the like
• CPC Class Codes: H01L 2224/0401 Bonding areas specifically adapted for bump connectors, e.g. under bump metallisation [UBM]
• CPC Class Codes: H01L 2224/04042 Bonding areas specifically adapted for wire connectors, e.g. wirebond pads
• CPC Class Codes: H01L 2224/06136 Covering only the central area of the surface to be connected, i.e. central arrangements
• CPC Class Codes: H01L 2224/13 of an individual bump connector
• CPC Class Codes: H01L 2224/1308 being stacked
• CPC Class Codes: H01L 2224/13082 Two-layer arrangements
• CPC Class Codes: H01L 2224/13084 Four-layer arrangements
• CPC Class Codes: H01L 2224/13099 Material
• CPC Class Codes: H01L 2224/131 with a principal constituent of the material being a metal or a metalloid, e.g. boron [B], silicon [Si], germanium [Ge], arsenic [As], antimony [Sb], tellurium [Te] and polonium [Po], and alloys thereof
• CPC Class Codes: H01L 23/49811 Additional leads joined to the metallisation on the insulating substrate, e.g. pins, bumps, wires, flat leads H01L23/49827 takes precedence
• CPC Class Codes: H01L 24/06 of a plurality of bonding areas
• CPC Class Codes: H01L 24/11 Manufacturing methods for bumps on insulating substrates H01L21/4853
• CPC Class Codes: H01L 24/13 of an individual bump connector
• CPC Class Codes: H01L 24/72 Detachable connecting means consisting of mechanical auxiliary parts connecting the device, e.g. pressure contacts using springs or clips
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00013 Fully indexed content
• CPC Class Codes: H01L 2924/01005 Boron [B]
• CPC Class Codes: H01L 2924/01006 : Carbon [C]
• CPC Class Codes: H01L 2924/01013 : Aluminum [Al]
• CPC Class Codes: H01L 2924/01014 : Silicon [Si]
• CPC Class Codes: H01L 2924/01019 : Potassium [K]
• CPC Class Codes: H01L 2924/01022 : Titanium [Ti]
• CPC Class Codes: H01L 2924/01027 : Cobalt [Co]
• CPC Class Codes: H01L 2924/01029 : Copper [Cu]
• CPC Class Codes: H01L 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/01039 : Yttrium [Y]
• CPC Class Codes: H01L 2924/01042 : Molybdenum [Mo]
• CPC Class Codes: H01L 2924/01044 : Ruthenium [Ru]
• CPC Class Codes: H01L 2924/01045 : Rhodium [Rh]
• CPC Class Codes: H01L 2924/01046 : Palladium [Pd]
• CPC Class Codes: H01L 2924/01047 : Silver [Ag]
• CPC Class Codes: H01L 2924/01049 : Indium [In]
• CPC Class Codes: H01L 2924/0105 : Tin [Sn]
• CPC Class Codes: H01L 2924/01074 : Tungsten [W]
• CPC Class Codes: H01L 2924/01077 : Iridium [Ir]
• CPC Class Codes: H01L 2924/01078 : Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/01082 : Lead [Pb]
• CPC Class Codes: H01L 2924/01322 : Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H01L 2924/014 : Solder alloys
• CPC Class Codes: H01L 2924/1433 : Application-specific integrated circuit [ASIC]
• CPC Class Codes: H01L 2924/3011 : Impedance
• CPC Class Codes: H05K 3/20 : by affixing prefabricated conductor pattern H05K1/187, H05K3/046, H05K3/4658, H05K3/4682 takes precedence
• CPC Class Codes: H05K 3/3421 : Leaded components

Abstract

Microelectronic contact structures are fabricated by separately forming, then joining together, various components thereof. Each contact structure has three components: a “post” component, a “beam” component, and a “tip” component. The resulting contact structure, mounted to an electronic component, is useful for making an electrical connection with another electronic component. The post component can be, fabricated on a sacrificial substrate, joined to the electronic component and its sacrificial substrate removed. Alternatively, the post component can be formed on the electronic component. The beam and tip components can each be fabricated on a sacrificial substrate. The beam component is joined to the post component and its sacrificial substrate is removed, and the tip component is joined to the beam component and its sacrificial substrate is removed. In an embodiment of the invention, the beam components of adjacent contact structures are disposed at different heights above the electronic component, whereby at least a portion of the first beam component can overlap at least a portion of the second beam component, thereby conserving space required to accommodate the beam components on the surface of the electronic component.

Claims

1. Method of mounting two microelectronic contact structures to an electronic component, comprising, for each microelectronic contact structure:

providing a post component on an electronic component;

fabricating a beam component;

fabricating a tip component comprising a tip structure;

joining the beam component to the post component; and

joining the tip component to the beam component such that the tip structure extends from the beam component;

disposing the beam of a one of the two microelectronic contact structures at a substantially different height from a surface of the electronic component than the beam component of another of the two microelectronic contact structures; and

disposing the tip components of each of the two microelectronic contact structures in substantially the same plane, the plane being substantially parallel to a surface of the electronic component.

2. The method of claim 1, further comprising disposing the tip components of each of the two microelectronic contact structures a first distance in a direction substantially parallel to the electronic component away from one another, and disposing the post components of each of the two microelectronic contact structures a second distance in the same direction away from one another, wherein the first distance is less than the second distance.

3. The method according to claim 1, wherein the fabricating a beam component step further comprises:

depositing a layer of masking material on a substrate;

forming an opening in the layer of masking material; and

depositing at least one layer of a metallic material in the opening, thereby defining a beam component in the opening.

4. The method of claim 1, wherein the providing a post component step further comprises the steps of:

fabricating the post component on a sacrificial substrate;

joining the post component to the electronic component; and

removing the sacrificial substrate.

5. The method of claim 1, wherein the fabricating a beam component step further comprises the steps of:

fabricating the beam component on a sacrificial substrate prior to the step of joining the beam component to the post component; and

removing the sacrificial substrate from the beam component after the step of joining the beam component to the post component.

6. The method of claim 1, wherein the fabricating a tip component step further comprises the steps of:

fabricating the tip component on a sacrificial substrate prior to the step of joining the tip component to the beam component, the tip component comprising at least one pointed tip feature and a standoff base attached to the pointed tip feature; and

removing the sacrificial substrate from the tip component after the step of joining the tip component to the beam component.

7. The method of claim 6, wherein the disposing the tip components step further comprises disposing the pointed tip features of each of the two microelectronic contact structures in the substantially the same plane.

8. In combination with an electronic component, a first contact structure and a second contact structure, each of the contact structures comprising:

a post component substantially perpendicular to the electronic component;

a beam component joined to the post component; and

a tip component joined to the beam component;

wherein a portion of the beam component of one of the contact structures is disposed over the beam component of the other contact structure, wherein the tip component of the first contact structure is positioned a first distance in a direction substantially parallel to the electronic component away from the tip component of the second contact structure, the post component of the first contact structure is positioned a second distance in the same direction away from the post component of the second contact structure, and the first distance is not equal to the second distance.

9. The first and second contact structures of claim 8, wherein the beam component of each of the contact structures further comprises a metallic material deposited by a method selected from electroplating, electroless plating, sputtering, physical vapor deposition, and chemical vapor deposition.

10. The first and second contact structures of claim 8, wherein the beam component of the first contact structure is disposed at a substantially different height from a surface of the electronic component than the beam component of the second, contact structure, and the tip components of each of the first and the second contact structures are disposed in substantially the same plane, the plane being substantially parallel to a surface of the electronic component.

11. The first and second contact structures of claim 8, wherein the first distance is substantially less than the second distance.

12. The contact structures according to claim 8, wherein the post component is joined to the electronic component.

13. The contact structures according to claim 8, wherein the electronic component further comprises a first terminal and a second terminal, and wherein the post component of the first contact structure is joined to the first terminal and the post component of the second contact structure is joined to the second terminal.

14. The contact structures according to claim 8, wherein the post component of the first contact structure and the post component of the second contact structure are built up upon the electronic component.

15. The contact structures according to claim 8, wherein the tip component comprises at least one pointed tip feature and a standoff base interposed between the at least one pointed tip feature and the beam component.